The GPI transamidase complex of Saccharomyces cerevisiae contains Gaa1p, Gpi8p, and Gpi16p.

ABSTRACT: Gpi8p and Gaa1p are essential components of the GPI transamidase that adds glycosylphosphatidylinositols (GPIs) to newly synthesized proteins. After solubilization in 1.5% digitonin and separation by blue native PAGE, Gpi8p is found in 430-650-kDa protein complexes. These complexes can be affinity purified and are shown to consist of Gaa1p, Gpi8p, and Gpi16p (YHR188c). Gpi16p is an essential N-glycosylated transmembrane glycoprotein. Its bulk resides on the lumenal side of the ER, and it has a single C-terminal transmembrane domain and a small C-terminal, cytosolic extension with an ER retrieval motif. Depletion of Gpi16p results in the accumulation of the complete GPI lipid CP2 and of unprocessed GPI precursor proteins. Gpi8p and Gpi16p are unstable if either of them is removed by depleti

SUBMITTER: Fraering P 

PROVIDER: S-EPMC60174 | biostudies-literature | 2001 Oct

REPOSITORIES: biostudies-literature